Password-protect a PDF
Add password protection to a PDF so it can only be opened with the password you set. Encryption uses AES-256 via qpdf compiled to WebAssembly and runs entirely in your browser.
Your files never leave your browser
How to use
- 1
Enter the password to open the file, and optionally a different owner password.
- 2
Drop your PDF files into the box.
- 3
Download the encrypted PDFs.
FAQ
Are my files or passwords uploaded?
No. Encryption runs locally through qpdf WebAssembly. Neither the file nor the password leaves your browser.
What is the owner password?
It unlocks editing and permission changes. If you leave it empty, the open password is used for both.
How strong is the protection?
AES-256, the strongest encryption the PDF format supports. It is only as strong as your password — use a long one.
Can I remove the password later?
Yes, with Unlock PDF, as long as you know the password.
Which PDF readers open the result?
Any modern reader: Adobe Reader, Preview, Chrome, Firefox, Edge and mobile apps.